\ assertions

\ Copyright (C) 1995,1996,1997,1999,2002,2003,2007 Free Software Foundation, Inc.

\ This file is part of Gforth.

\ Gforth is free software; you can redistribute it and/or
\ modify it under the terms of the GNU General Public License
\ as published by the Free Software Foundation, either version 3
\ of the License, or (at your option) any later version.

\ This program is distributed in the hope that it will be useful,
\ but WITHOUT ANY WARRANTY; without even the implied warranty of
\ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
\ GNU General Public License for more details.

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\ along with this program. If not, see http://www.gnu.org/licenses/.

variable assert-level ( -- a-addr ) \ gforth
\ All assertions above this level are turned off.
1 assert-level !

: assertn ( n -- ) \ gforth assert-n
    \ this is internal (it is not immediate)
    assert-level @ >
    if
	POSTPONE (
    then ;

: assert0( ( -- ) \ gforth assert-zero
    \ Important assertions that should always be turned on.
    0 assertn ; immediate restrict
: assert1( ( -- ) \ gforth assert-one
    \ Normal assertions; turned on by default.
    1 assertn ; immediate restrict
: assert2( ( -- ) \ gforth assert-two
    \ Debugging assertions.
    2 assertn ; immediate restrict
: assert3( ( -- ) \ gforth assert-three
    \ Slow assertions that you may not want to turn on in normal debugging;
    \ you would turn them on mainly for thorough checking.
    3 assertn ; immediate restrict
: assert( ( -- ) \ gforth
    \ Equivalent to @code{assert1(}
    POSTPONE assert1( ; immediate restrict

: assert-throw  true abort" assertion failed" ;

: ) ( -- ) \ gforth	close-paren
    \ End an assertion.
    postpone 0= postpone IF postpone ~~ postpone assert-throw
    postpone THEN ; immediate